Dental tool.



-C. H. DAVIS, DECD.

B. B. DAVIS! EXECUTRIX.

DENTAL TOOL.

APPLICATION man FEB. 2, ms.-

1,299, 1 37. Patented Apr. 1,1919.

qfihacwe CSwwmmXow nine.

.CHARLES H. DAVIS, OF WORCESTER, MASSACHUSETTS; BERTHA B. DAVISEXECUTBIX OF CHARLES H. DAVIS, DECEASED.

DENTAL TOOL.

Specification of Letters Patent.

Patented Apr. 1, 1919.

To all whom it may concern:

Be it known that I, CHARLES H. DAVIS, a citizen of the United States,residing at Worcester, in the county of Worcester, State 4 ofMassachusetts, have invented a certain new and useful Improvement inDental Tools, of which the following is a specification, reference beingbad therein to the accompanying drawings.

This invention relates to dental tools, but more particularly to such asare used in cleaning, polishing or grinding teeth, and has for itsobject to provide a structure which is more eiiicient than any devicesof a similar nature heretofore known.

In the case of tooth cleaning devices consisting wholly or partially offlexible or semi-flexible material, and particularly those having atleast the central portion of rubber or other pliable or resilientmaterial, great difliculty has been found in securing means for holdingthe same so that relative rotation is impossible. that such pliable orresilient centers shall not be cut by the holding means, and thatfreedom of action shall be obtained.

One feature of the present invention is the mandrel in which the hub ofthe tooth operating tool is bound by the forcing of the flexible orresilient material of such hub substantially away from the axis of thebinding screw or other member performing this function. A second featureis the formation of the mandrel head with indentations or perforationstherein in which the flexible material of the hub of the tooth operatingtool is forced or held by the action of the binding member. Anotherfeature is the formation upon the hub of the tooth operating tool ofprojections adapted to enter corresponding indentations or orifices inthe mandrel, so that such tool will be rigidly'positioned and maintainedtherein to facilitate the insertion of the binding screw or. othersimilar means, and when bound therein by the action of such screw to actin conjunction with the inner or bind ing face of the mandrel to preventrelative rotation of the mandrel and tooth operating tool. A furtherfeature of the invention is the tool having a rigid or substantiallyrigid operating portion and a flexible or resilient central portion orhub which will provide a firm grip upon the mandrel and will permit offreedom of action of the tool and rocking of such tool relative to theaxis of the mandrel.

Many other features and advantages of the invention will be describedhereinafter and included in the claims.

Referring to the drawings:

Figure 1 is a side elevation of one embodiment of the invention.

Fig. 2, central longitudinal section of the embodiment shown in Fig. 1with the parts in their relative position for assembling.

Fig. 3, same as Fig. 2, but with the parts assembled.

Fig. 4, side elevation of the tooth operating tool detached from themandrel, as will be fully described hereinafter.

Fig. 5, side elevation of a modified form of the invention, as will befully described hereinafter.

Fig. 6, side elevation of the tooth operating tool in the embodiment ofthe invention shown in Fig. 5, as will be fully described hereinafter.

Fig. 7 central longitudinal section of a further modification of theinvention, as will be fully described hereinafter.

Fig. 8, side elevation of a modified form of the tooth operating tool,as will be fully described hereinafter.

In the embodiment of the invention shown in Figs. 1 to 4 inclusive, theinvention is shown to comprise a mandrel 20 formed with a shank 21adapted to be inserted in the usual form of rotary shaft machine foundin dental operating rooms. At the forward end of this shank is formedthe head 22 which is adapted to receive and hold the hub of the toothoperating tool 23 here shown of the rubber cup variety. For the sake ofsimplicity of description this tooth operating tool will be hereinafterreferred to as the tool, and while this tool is shown of the cup varietyit should be clearly understood that any of the many forms of dentaltools might be substitutedtherefor, provided they are constructed with aflexible, resilient or expansible hub or central portion, or the evidentequivalent thereof.

In this embodiment of the invention, the head is formed substantiallycup shaped with the outer rim of the cup extending substantiallyparallel to the axis of the mandrel, and it has been found to beadvantageous that the inner or operating face of such head should besubstantially cup shaped or with its side walls projecting forwardlyfrom the center or base of this face of the mandrel for the reasonswhich will be readily evident from the following description. In theinside walls of this head are here formed one or more indentations ororifices 24 to receive the hub of the tool 23, though these indentationsor orifices are not essential to the construction as will be describedin connection with the embodiment shown in Fig. 7 While it is in no wayessential that these indentations 24 should pass through the walls ofthe head, it has been found that this is the easiest method of formingthem. Projecting forwardly from the base of the operating face of themandrel is preferably constructed a member 25 through which passes thethreaded hole 26 concentric with the axis of the mandrel. This threadedhole is adapted to receive the binding screw 26 and the outer extremityof the member '25 forms a seat for the head of this screw to preventsuch head from advancing into contact with the base of the operatingface of the mandrel. This seat for the head of the screw has been foundto be very advantageous in preventing the screw from advancingsufficiently to force its way entirely through the hub of a tool inwhich the flexible or resilient portion of the hub is larger than thediameter of the head of the screw. hen indentations or orifices 24: areformed in the head of the mandrel, it has been found to be somewhatadvantageous to form corresponding projections 27 on the hub of the toolfor the reason which has been stated in connection With the indentations24, but these are not essential as will be fully explained in connectionwith the embodiment shown in Fig. 7

In Fig. 5 is shown a modification of the invention in which theindentations or orifices 28 in the head 29 of the mandrel 30 are oblonginstead of round as was the case of the embodiment shown in Figs. 1 to 4inclusive. Vith this form of indentations or orifices it is advantageousto use a tool having projections 31 thereon corresponding to andpreferably fitting the indentations or orifices 28 as is shown in Fig. 6of the drawings.

In the embodiment shown in Fig. 7 the structure is substantiallyidentical with those shown in Figs. 1 to 6 inclusive with the exceptionthat no indentations or orifices are formed in the head 32 of themandrel 33. In this figure the tool is shown entirely composed of rubberand through the center thereof is an orifice 34 through which passes thebinding screw 35 and this central orifice 34 is preferably of smallerdiameter than the head 36 of the screw so that when such screw isadvanced in the tapped hole in the mandrel in the usual manner, the hubis expanded by the wedging action of the head and such head advancesuntil it becomes seated in the member 37. This expanding of the hub bythe action of the head of the binding screw or pin forces the outer wall38 of the hub against the opposing inner face of the mandrel and thuscauses the tool to be bound about the periphery of such hub as well asagainst the base of the cup face of the mandrel. It has heretofore beencommon practies to bind a tool upon a mandrel with a binding screw, andno invention is claimed on this structure when broadly construed,

but it is believed that in all cases heretofore the binding has beenperformed by pressure exerted substantially parallel with the axis ofthe binding screw only. Where such material as rubber having certainadhesive or gripping qualities is used, it has been found that generallysuflicient hold will be obtained on the tool to prevent relativerotation of such tool and the mandrel, but the use of an indented orperforated head gives additional holding power which insures absolutehold.

In the latter case not only are the projections upon the hub, if theseare used, held within such indentations or orifices, but a certainamount of material forming the body of the gub is forced therein as willbe readily evient.

In Fig. 8 of the drawings is shown a modified form of tool in which thecup shaped or operating portion 39 thereof is constructed of abrasivematerial and the central portion or hub 40 is of flexible or resilientmaterial to permit of ready use in the mandrel described in Figs. 1, 2,3, 5 and 7 In this form of tool the hub may be formed separate from theoperating portion and either cemented, vulcanized or otherwise fastenedthereto, or they may be formed integral and the operative portionprovided with the abrasive material and vulcanized or otherwise treatedto produce a rigid or semi- -rig id portion if desired.

In all the embodiments herein shown and described, it is advisable tomake the head of the screw with its upper and lower faces, orparticularly the lower one either conical or rounded to facilitate thehub expanding action thereof and to obviateany possibilityof the rubberor other hub material being cut by the sharp edges thereof, though itshould be clearly understood that this is not essential to theconstruction.

What I claim as my invention and desire to secure by Letters Patentis 1. In a device of the class described, a tool provided with aprojecting hub, a mandrel having a socket formed therein to receive theprojecting portion of said hub, the walls of said socket being indented,and means for expanding said hub within said socket.

2. As an article of manufacture, a tool, a said face when the tool is inits bound posimandrel provided with an axial erforation, tion in themandrel. 10 a headed pin ada ted to pass '0 rough said In testimonywhereof I aflix my signature tool and have its orward portion heldwithin the presence of two Witnesses.

in said erforation to secure said tool to said CHARLES H. DAVIS. mandreand means projecting from the Witnesses:

binding face of said mandrel for maintain- HARTLEY W. BARTIE'I'I,

ing the head of such pin at an interval from HANNAH M. KENNEDY.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner 01' Iatents, Washington, D. 0.

